The invention relates to nematic liquid crystalline mixtures for the use in optoelectronic components (displays) for the modulation of passing or transmitted light, as well as for the rendition of numbers, symbols and images. The invention can be used for the production of optoelectronic components (displays) for watches, computers, and other devices.
A great number of liquid crystalline, predominantly nematic, compounds are known; (D. Demus, H. Demus, H. Zaschke: Flussige Kristalle in Tabellen, VEB Deutscher Verlag fur Grundstoffindustrie Leipzig, 2. edition. 1976). None of the known compounds have in their pure state characteristics, which would allow using them directly in optoelectronic components. It is known, however, that by mixing several compounds, the characteristics can be changed so that the melting and clarification temperatures, the threshold voltage, the dielectric and optical anisotropy, the viscosity and other characteristics allow utilization of the mixture in optoelectronic components. New components are constantly needed for changing the characteristics of the mixtures, in order to improve the mixtures in the direction required by the new technical developments. One of the important objects consists thereby in obtaining mixtures of high clarification temperatures, however, by simultaneously obtaining favorable switching times. In order to obtain high clarification temperatures, substances having an extensive linear ring system can be added whereby, however, also the viscosity and thus the switching times are strongly increased. (H. Kelker, R. Hatz: Handbook of Liquid Crystals, Publisher Chemie, Weinheim 1980).